Search results for "Adaptive"
showing 10 items of 792 documents
Generalization of Canny–Deriche filter for detection of noisy exponential edge
2002
This paper presents a generalization of the Canny-Deriche filter for ramp edge detection with optimization criteria used by Canny (signal-to-noise ratio, localization, and suppression of false responses). Using techniques similar to those developed by Deriche, we derive a filter which maximizes the product of the first two criteria under the constraint of the last one. The result is an infinite length impulse response filter which leads to a stable third-order recursive implementation. Its performance shows an increase of the signal-to-noise ratio in the case of blurred and noisy images, compared to the results obtained from Deriche's filter.
Neural based MRAS sensorless techniques for high performance linear induction motor drives.
2010
This paper proposes a neural based MRAS (Model reference Adaptive System) speed observer suited for linear induction motors (LIM). Starting from the dynamical equation of the LIM in the synchronous reference frame in literature, the so-called voltage and current models of the LIM in the stationary reference frame, taking into consideration the end effects, have been deduced. Then, while the inductor equations have been used as reference model of the MRAS observer, the induced part equations have been discretized and rearranged so to be represented by a linear neural network (ADALINE). On this basis, the so called TLS EXIN neuron has been used to compute on-line, in recursive form, the machi…
Urban gardens and institutional fences: The case of communal gardens in Turin
2017
Urban gardens take on different forms and meanings, which vary depending on the socio-economic context where they located/used and how it evolves over time. This makes a garden comparable to a micro-social ecosystem, different from other gardens and ever changing. As with every social-ecosystem resulting from a territorialisation process, there is a certain degree of social inertia that makes it difficult for outsiders with new motivations and demanding new spaces to enter into the "garden ecosystem". Drawing on existing literature and fieldwork in two urban communal gardens in Turin, the paper is mainly concerned with the spatiotemporal dimension of urban gardening, with a special focus on…
A Maximal-Space Algorithm for the Container Loading Problem
2008
In this paper, a greedy randomized adaptive search procedure (GRASP) for the container loading problem is presented. This approach is based on a constructive block heuristic that builds upon the concept of maximal space, a nondisjoint representation of the free space in a container. This new algorithm is extensively tested over the complete set of Bischoff and Ratcliff problems [Bischoff, E. E., M. S. W. Ratcliff. 1995. Issues in the development of approaches to container loading. Omega 23 377–390], ranging from weakly heterogeneous to strongly heterogeneous cargo, and outperforms all the known nonparallel approaches that, partially or completely, have used this set of test problems. When …
Learning vector quantization with alternative distance criteria
2003
An adaptive algorithm for training of a nearest neighbour (NN) classifier is developed in this paper. This learning rule has some similarity to the well-known LVQ method, but uses the nearest centroid neighbourhood concept to estimate optimal locations of the codebook vectors. The aim of this approach is to improve the performance of the standard LVQ algorithms when using a very small codebook. The behaviour of the learning technique proposed here is experimentally compared to those of the plain k-NN decision rule and the LVQ algorithms.
Moving Toward a Strategy for Addressing Climate Displacement of Marine Resources: A Proof-of-Concept
2020
Realistic predictions of climate change effects on natural resources are central to adaptation policies that try to reduce these impacts. However, most current forecasting approaches do not incorporate species-specific, process-based biological information, which limits their ability to inform actionable strategies. Mechanistic approaches, incorporating quantitative information on functional traits, can potentially predict species- and population-specific responses that result from the cumulative impacts of small-scale processes acting at the organismal level, and can be used to infer population-level dynamics and inform natural resources management. Here we present a proof-of-concept study…
A central role for Notch in effector CD8(+) T cell differentiation.
2014
Activated CD8(+) T cells choose between terminal effector cell (TEC) or memory precursor cell (MPC) fates. We found that the signaling receptor Notch controls this 'choice'. Notch promoted the differentiation of immediately protective TECs and was correspondingly required for the clearance of acute infection with influenza virus. Notch activated a major portion of the TEC-specific gene-expression program and suppressed the MPC-specific program. Expression of Notch was induced on naive CD8(+) T cells by inflammatory mediators and interleukin 2 (IL-2) via pathways dependent on the metabolic checkpoint kinase mTOR and the transcription factor T-bet. These pathways were subsequently amplified d…
Robust adaptive algorithm with low computational cost
2006
An adaptive algorithm, which is robust to impulsive noise, is proposed. The cost function underlying this algorithm contains a parameter that controls the immunity to impulsive noise and can be easily adapted. Moreover, weight updating involves a nonlinear function, which recently has been shown to have an efficient hardware implementation. The proposed adaptive algorithm has been successfully tested in terms of accuracy and convergence on a system-identification simulation.
On-Sky Tests of a High-Power Pulsed Laser for Sodium Laser Guide Star Adaptive Optics
2016
We present results of on-sky tests performed in the summer of 2013 to characterize the performance of a prototype high-power pulsed laser for adaptive optics. The laser operates at a pulse repetition rate (PRR) of 600–800[Formula: see text]Hz, with a 6% duty cycle. Its coupling efficiency was found to be, in the best test case (using 18[Formula: see text]W of transmitted power), [Formula: see text] photons s[Formula: see text] sr[Formula: see text] atom[Formula: see text] W[Formula: see text] m2 when circular polarization was employed and [Formula: see text] photons s[Formula: see text] sr[Formula: see text] atom[Formula: see text] W[Formula: see text] m2 with linear polarization. No impro…
Towards Robust Adaptive Least-Squares Parameter Estimation with Internal Feedback
1998
Abstract The new concepts of the ‘covariance matrix normalization’ and the ‘cascade’ structure of the adaptive least-squares estimator are shown to generalize and extend the use of internal information feedback in various robustness/alertness-oriented modifications to the standard ALS estimation algorithm. In the cascade estimation structure it is possible to ‘naturally’ stabilize, rather than maximize, the information matrix so that the covariance windup and blowup are effectively eliminated and the celebrated square root update of the covariance matrix is no longer needed Consequently, a new, ‘single-loop/cascade’ ALS MIMO estimation algorithm, enabling to effectively track both slow and …